New “Flying Tea Kettle” Could Get Us To Mars in Weeks, Not Months

At 54.6 million km away at its closest, the fastest travel to Mars from Earth using current technology (and no small bit of math) takes around 214 days — that’s about 30 weeks, or 7 months. A robotic explorer like Curiosity may not have any issues with that, but it’d be a tough journey for a human crew. Developing a quicker, more efficient method of propulsion for interplanetary voyages is essential for future human exploration missions… and right now a research team at the University of Alabama in Huntsville is doing just that.

This summer, UAHuntsville researchers, partnered with NASA’s Marshall Space Flight Center and Boeing, are laying the groundwork for a propulsion system that uses powerful pulses of nuclear fusion created within hollow 2-inch-wide “pucks” of lithium deuteride. And like hockey pucks, the plan is to “slapshot” them with plasma energy, fusing the lithium and hydrogen atoms inside and releasing enough force to ultimately propel a spacecraft — an effect known as “Z-pinch”.

“If this works,” said Dr. Jason Cassibry, an associate professor of engineering at UAH, “we could reach Mars in six to eight weeks instead of six to eight months.”

The key component to the UAH research is the Decade Module 2 — a massive device used by the Department of Defense for weapons testing in the 90s. Delivered last month to UAH (some assembly required) the DM2 will allow the team to test Z-pinch creation and confinement methods, and then utilize the data to hopefully get to the next step: fusion of lithium-deuterium pellets to create propulsion controlled via an electromagnetic field “nozzle”.

Although a rocket powered by Z-pinch fusion wouldn’t be used to actually leave Earth’s surface — it would run out of fuel within minutes — once in space it could be fired up to efficiently spiral out of orbit, coast at high speed and then slow down at the desired location, just like conventional rockets except… better.

“It’s equivalent to 20 percent of the world’s power output in a tiny bolt of lightning no bigger than your finger. It’s a tremendous amount of energy in a tiny period of time, just a hundred billionths of a second.”

– Dr. Jason Cassibry on the Z-pinch effect

In fact, according to a UAHuntsville news release, a pulsed fusion engine is pretty much the same thing as a regular rocket engine: a “flying tea kettle.” Cold material goes in, gets energized and hot gas pushes out. The difference is how much and what kind of cold material is used, and how forceful the push out is.

Everything else is just rocket science.

Read more on the University of Huntsville news site here and on al.com. Also, Paul Gilster at Centauri Dreams has a nice write-up about the research as well as a little history of Z-pinch fusion technology… check it out. Top image: Mars imaged with Hubble’s Wide-Field Planetary Camera 2 in March 1995.

Depending on what you mean by “real” of course. It is a (rather generic) prestudy of pulsed fusion concepts, it isn’t going to be developed to a propulsion system. “If this works” is a weasel word for the latter, not describing the former which is what will be realized within the study.

That said, it is exciting that people invest in far out, positive thinking schemes. My problem is with the hot air, not with the actual research.

Tokamaks has already shown that fusion can be achieved (break even) even if they haven’t done it in one machine on one setting yet – ITER will test that – and even if they may never get economy out of it – DEMO is supposed to test that.

So even if Z-pinches won’t work – and they probably won’t, since the instabilities of small plasmas are a huge problem – some day a fusion device may be available to power a propulsion system, in principle.

First, it is a pulsed machine, you regulate average acceleration by rate of pulses. That can be done, the V-1 pulsed jet machine showed that under WWII.

Second, even though the reaction products can be high velocity, they can be throttled. See the NASA concept drawing at Centauri Dreams, where they can modify anode-cathode voltage, running the MHD generator used to extract capacitor bank energy backwards as it were.

Third, they can in principle choose to size fuel pucks, same as they want to size nukes powering Orions for different propulsion modes. But I don’t know how much that could be done in a Z pinch, assuming it works.

The short trip time is mainly to circumvent the radiation problem. Actually it isn’t too bad according to NASA studies, the background would be 2-3 times the ISS exposure. That is why they can plan for year long NEO missions by using today’s ISS modules, and having merely an extra shielded connection module to retreat to during lethal CMEs.

The larger risk, as for the ISS, seems to be that an ISS module will get a calculated leak from an impact on an average 30 years. If you go out for years and many missions, that risk will catch up to you.

That said, radiation effects, prolonged zero to low (Mars) gravity and the lowered immune system of space are severe problems that need to be studied and overcome.

Other problems include medicine and surgery in low gravity environments, as well as the inability to close an artificial biosphere as of yet. At todays ~ 50 – 70 % of closure, you may not make it to an NEO and back. Even the ISS gets and store supplies more often,

What I would like to see would be two super-fast probes sent in opposite directions from Earth to keep measuring parallax and thus giving us a better idea of interstellar distances in our local neighborhood.

Hmm… The part that I like is at the bottom of the linked article “UAHuntsville news release” where it is stated that this engine: “Alternatively, it could be attached to an asteroid and run for months to gently nudge its trajectory away from Earth.”…. meaning it could be used for asteroid mitigation….. or:

Yeah, yeah.. identify the right rock then go out there and mount motors on it. Bring it into Earth orbit, hollow it out for crew quarters and command and control systems. Then spin it up for artificial gravity and use that baby as a space ship! Deep space exploration anybody?

The right water rich rock would provide radiation shielding, auxiliary propellant and BONUS… an oxygen supply.

When I said, “The right water rich rock…” I was leaning toward a body
with more structural integrity and quiescence then an active comet. In
recent years a number of what were presumed to be inactive asteroids
were apparently seen to out gas and become ‘comet like’. Some of these incidences may be attributed to collisions with other asteroids?

This is the usual over-pitched press release that media can inflate to a hot air balloon. Somewhat counterproductive, since there are definitely groups of people that sees this constant repetition as tedious. [Disclaimer: I am one of them.] I assume Centauri Dreams is an outlet and producer of these “dreams”.

The Z pinch was abandoned because it was less mature and harder to develop than the tokamak that quickly surpassed it. Even tokamaks have ~ 40 – 50 years left before delivering a prototype according to current plan, if they get the money they need to go full clip – doubtful.

This means that easier to build stationary fusion plants will take at least 2 human generations (~2*25 years) to emerge. Note by the way here that the Centauri Dream article can’t be bothered to check out the after much work established and published fusion plans. It chooses instead to peddle the urban myth that fusion is “always just a decade or two away from realization”.

This is to all accounts a prestudy of what it would take to transform a working method of fusion into a space propulsion system. They don’t intend to work on the Z pinch itself, and it is doubtful any funding source will ever pay for that.

To take a point from the Centauri Dream article and apply it more centrally to the context, if the results from the UA Huntsville research is seen as failed to meet expectations by the paying public (NASA participation), doesn’t this kind of research and its presentation lead to public relations problems?

VASIMR is feasible (for some purposes if not interplanetary propulsion), let us hope their test unit will make it to ISS soon. The Sun-Earth L2 Lagrange point way station that scientists so long have spoken for instead of ISS, and is now considered by NASA again, may be taken there by a conceptual plasma propulsion + solar panel energy system massing some 30-40 ton I take it (need SLS or Falcon Heavy), which is … what do they say … oh, huge! =D

I concur with you TL, one of the major products of fusion is huge doses of gamma rays which cause all sorts of problems for men and material that haven’t been broached because they haven’t yet got past the problems of stable plasma containment. VASIMR really needs a nuclear reactor or some other clever power source (solar reflector?) to be powerful enough for Mars travel.

There’s nothing wrong with the design since there is no design… This is very very basic research (nothing wrong with that) wrapped with 2 miles of speculative application bubble wrap, but the shipping label already gives numbers on how long it will take for such a ship to travel to Mars, which is ridiculous. (For example, the ISP may be high, but if the dry weight is high, it’s completely useless for the relatively short trip to Mars)

And actually, even the research hasn’t been done yet. The university got a hand-me-down machine. One of the things the university MIGHT do with it is conduct this basic research. Which even at this level is speculative.

In the past few years we have seen drones and robots replace humans in the dangerous environment of war, eventually we’ll see the same in space exploration, in fact, we already have. Why waste so much on getting an actual human to Mars (or any other planet) when a robot can do the job better, cheaper & quicker?

I basically agree. My amateur opinion is that by the time the technology exists to actually transport humans these great distances the same tech will have already given birth to the inorganic life forms that surpass humanity. Or humans will merge with their tech.

Biology is still far ahead of technology, especially when it comes to the ability to regenerate oneself after injury and in human-level intelligence, which, contrary to the statements of individuals like Ray Kurzweil, not even infinite computing power can outdo in terms of originality and creativity. If you’re captured by extraterrestrials (just a scenario, I’m not an exopolitics believer) no computer will be programmed for the situation and will hence be useless.

might be true now, but i think there is an inevitable point at which tech will simply have more ‘computing’ ability than the human brain & sentience isn’t far behind. or humans enhanced by incorporated technology will dominate.

I have seen the Sandia Z machine at work. It is fairly impressive. The Z pinch concept sounds simple enough. Suppose there is a tube of plasma you want to confine. Since this is a plasma with free charges the conductivity is large and you can run a current through it. For a static situation (artificial, but works for in principle thinking) the Faraday equation gives ?xB = 4?j for B the magnetic field, j a current density and ? the nabla differential operator. The cross product with this operator on the magnetic field (called a curl) means that if the magnetic field is along a plasma tube the magnetic field winds around that tube. The moving charges then are defected perpendicular to the field and confined in the tube. It all sound great, right?

There are problems. If you could arrange for that tube to be infinitely long then there would be no problem. In fact this is an exercise in the Jackson E&M text as well as Chen’s book on plasma physics. The problem is it is not infinite and you have to cut off the ends. You then have to employ a strong magnetic mirror field at the ends to try to clamp it off. However, it is not possible to completely clamp it off because the magnetic field has no monopole charge. The clamping off also introduces perturbations that amplify and destroy the plasma. Plasmas are just plain weird, and things like Rayleigh-Taylor instabilities (instabilities at the boundary of a fluid or plasma) no matter how small can grow rapidly into chaos.

So what do you do? You can bend the tube into a torus, which is the tokomak design. However the field strength of the magnetic field on the outer portion of the torus is less than the interior, so one must do all sorts of fancy stuff with poloidal fields and the like. Either that or one uses the original design in a pulsed transient mode. The results are so far very disappointing. The tokomak approach is leading the way, but if the ITER fails to deliver much the whole fusion industry in applied physics might come to an illustrious end.

This idea is to use the tube approach in a transient pulse that uses fusion energy to send a projectile. It sounds good, but this has a long way to go just working on the ground, let alone getting something like this in space.

This origin of this technology is actually decades old. The Russians disabled one of our spy satellites back in the late 80’s with an unknown E/M weapon MUCH to the chagrin of the Pentagon who demanded to know – HOW DID THEY DO THAT? It turned out that the Russians were using shaped charges exploded in a copper cylinder wrapped in coils of stainless steel tubing containing a low temperature superconducting liquid. Micro seconds before the shaped charge exploded a bank of high voltage capacitors simultaneously discharged into the coils.. the beam propagated by this device was in the 250,000,000 watt range…. Since then, our military has adapted and modified this design. As E/M counter measures weapons, they are currently (pun intended?) deployed in rockets, bombs and suitcases. As an E/M counter measure and vehicle disabling weapon, they are quite effective. During the Gulf War, one of these devices was exploded over an Iragi tank battalion.. they were literally stopped in their tracks….. then picked off one at a time.

So.. the lithium deuteride cylinders are part of this technology’s maturation?